Max ulljcann



Patented Nov. 21, 1922.

UNITED STATES PATENT OFFICE.

MAX ULLMANN, OF ZWICKAU, GERMANY, ASSIGNOR TO KARL WERTH, OF THE HAGUE,

HOLLAND. y

PRODUCTION OF NEGATIVES.

Application filed January 2, 1914. Serial No. 810,092.

(GRANTED UNDER THE PROVISIONS 0F THE ACT 0F MARGH 3, 1921, 4]. STAT. L.,1313.)

To all whom, it fm r/,g/ concern Y Be 1t known that I, MAX ULLMANN, acitizen of Germany, and a resident ot Zwickau, Saxony, Germany, haveinvented certain new and use'ul Improvements in the Production ol?Negatives, or" `which the 'lollowing is a specitication` The inventionrelates to a process :tor the production of negatives from originalswhich are adapted to relect light from at least a portion of theirsurfaces and the object is to provide quickly and cheaply a welldeiined,direct copy of the original, more particularly with a view for furtheruse in the production of plates :tor printing.

My invention will best be understood by reference to the followingdescription of an illustrative embodiment thereof taken in connectionwith the accompanying diagrammatic drawings. wherein Fig. 1 is a planview with parts successively broken away illustrating the process ofcopying,

Fig. 2 is a section on the line 2 2 ot Fig. 1,

Fig. 8 is a plan ot the negative, and

Fig. l is a section on the line l1-4; et Fig. 3.

It will be understood that in the drawin the thickness of the variouslayers is enormously exaggerated.

In practicing my invention, l may providey a translucent carrier 10,such as a glass plate, which carries a translucent iilin l1 ot chromatedcolloid, such as bi-chromated gelatine. This is laid on the original 12which is to be copied with the iilm 1l in face to tace contacttherewith, as illust-rated in Fig. 2, and light rays 13 from a suitablesource are passed through the layers l0 and ll and are reflected at i4'from the white portions of the original but are absorbed by the blackportions Such as ordinary print. The portions of the sensitive film llopposite the white portions oiz the original. are thus renderedyinsoluble by the reflected light. The negative is then washed in wateror dilute acid to remove the portions which have not been so renderedinsoluble. There is thus produced on the plate 10 a negative defined bythe insoluble portions of the chromate colloid layer and exhibiting thedesign corresponding to the black or colored design of the original inintaglio where the soluble colloid has been washed away. After thewashing. the plate is dipped in one or more suitable coloring or dyeingbaths, ior example, a bath ot' soluble aniline dye such as methylviolet, and the parts of the colloid layer remaining on the plate arcthus colored and made relatively opaque, the plate 10 being resistant tothe dye. The resulting negative may be further used in the production ofprinting plates and forms, 'for example, it may be copied upon asensitized printing plate and printing carried on by the offset processin the usual way.

In Fig. 1 portions of the capital R representing the original on theimage are section lined for black merely to indicate that they arebeneath the plate 10 and film 11. As the latter are transparentobviously the image would show with practically complete intensity. InFig. 3 representing the negative the dyed colloid iilm is lined torepresent purple, this being merely for purposes of illustration and notby way of limitation to a particular color.

The film ll or bi-chromated colloid is au example of atranslucentmaterial adapted without substantial change in its lighttrans mitting properties to be rendered differentially soluble by theaction o1 light so that a portion thereof may thereafter be selectivelydissolved by a suitable reagent and washed away. Because it does notprint out it may be subjected to the actinic action ot light for anadequate time. This is of a particular advantage when the original to becopied is printed on both sides, as, Jfor example, in reproducing abook. It has been found that no difficulty is encountered with shadowsfrom the printed matter on the reverse side of the original not incontact with the colloid film and I believe this to be the case becausethe passage oi. the light is .not immediately obstructed as soon as thematerial is exposed to light, but a continued action of the reflectedlight is permitted which, metaphorically speaking, burns out any shadowswhich might be due to a slight absorption of the light by printedYmattei' on the reverse side of the original.

The materials utilized in the process are very cheap and may be handledwithout the aid of a camera and with ordinary care may be manipulated indaylight.

Having thus described one embodiment of my invention, and Withoutlimiting myself thereto, what I claim as new and desire to secure byLetters Patent, is as follows:

1. A process of producing negatives from originals 'adapted to reflectlight from a portion of their surfaces which comprises placing over theoriginal a film of translucent material which becomes differentiallysoluble under the action ot light Without substantial change in itslight transmitting properties, transmitting light therethrough to bereflected in part from the original, washing out the soluble portions ofthe film and dyeing the remaining portions to produce an image.

2. A process for the production of negatives from originals adapted toreflect light from a portion of their surfaces which coinprises placinga bi-chromated colloid film mounted on a translucent carrier :face toface with the original, transmitting light therethrough to he reflected.in part from the original, Washing the carrier and film to removeunaffected portions of the film and dyeing the remaining portions toproduce an image.

3. A process for the production of negatives from originals adapted toreflect light from a portion of their surfaces which comprises placing abi-chromated colloid film mounted on a translucent carrier face to facewith the original, transmitting' light therethrough to be reflected inpart from the original, Washing the carrier and film to removeunaffected portions of the film and dyeing the remaining portions toproduce an image7 said carrier being resistant to the dye.

4. A process of producing negatives from originals Which are `adapted toreflect light from a portion oit their surfaces which includes the stepof placing over the original a translucent sheet comprising a film ofbichromated colloid and transmitting light therethrough to be reflectedin part from the original thereby to forni a negative image in thehi-chromated colloid.

In testimony whereof I afiix my signature in presence of two Witnesses.

MAX ULLMANN Witnesses lVALDnMAR HAUPT, HENRY HAsPER.

